go-clean-architecture

# Go Clean Architecture A Go service organized into four concentric layers — Domain, Usecase, Repository, Delivery — where source code depends *inward only*. Done well, the HTTP framework and the database are interchangeable details; the business logic is testable without either. This skill is framework-agnostic. Swap Gin for Fiber, Echo, Chi, or `net/http` by replacing the delivery layer — zero changes elsewhere. ## Core Rules 1. **Dependency Rule.** Source depends inward: Delivery → Usecase → Domain. Repository implements interfaces declared in Domain. Domain depends on nothing. 2. **Framework is a detail.** Gin/Fiber/Echo/Chi/net-http types live only in `internal/delivery/`. Usecases see plain Go values. 3. **Database is a detail.** SQL, sqlx, sqlc, pgx, GORM live only in `internal/repository/`. Usecases see repository interfaces. 4. **Domain owns the interfaces; layers below provide implementations.** `UserRepository` is an interface in `internal/domain`; the Postgres struct is in `internal/repository` and unexported. 5. **DTOs at the edges.** Delivery layer maps HTTP request bodies to domain inputs and domain entities to response bodies. Usecases never see `*gin.Context`, `http.Request`, or DB rows. 6. **`cmd/<binary>/main.go` is the only place that knows the whole system.** Wiring (DI) is explicit, framework-free Go code. ## When This Pays Off | Symptom | What clean architecture buys you | |---|---| | HTTP handlers contain SQL | Move SQL into a repository; handler...